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Draft Agenda

Study of an Improved Comprehensive Magnetic Field Inversion Analysis for Swarm Progress Meeting 2, E2Eplus Study. Work performed by Nils Olsen, Terence J. Sabaka, Luis R. Gaya-Pique, Lars Tøffner-Clausen, and Alexei Kuvshinov, Presented by: Nils Olsen. Draft Agenda.

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Draft Agenda

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  1. Study of an Improved Comprehensive Magnetic Field Inversion Analysis for SwarmProgress Meeting 2, E2Eplus Study Work performed by Nils Olsen, Terence J. Sabaka, Luis R. Gaya-Pique, Lars Tøffner-Clausen, and Alexei Kuvshinov, Presented by: Nils Olsen

  2. Draft Agenda 09:30 Welcome 09:35 Presentation of activities done so far (NIO)     Results obtained since MTR           First results of multi-satellite in-flight alignment           First results of (some) failure and Imperfection cases         Status of GUC     Plans for the near future 13:00 Lunch 14:00 General discussion     Possibility for a telecon with Terence J. Sabaka, GSFC 16:00 Adjourn 03. November 2006 | PM2 E2Eplus | page 2

  3. E2Eplus Study Logic • Status of June 2006 (MTR): • New, fast orbit generation scheme • Gradient approach • Multi-satellite alignment (tests partly concluded) • Status of November 2006 (PM2): • Multi-satellite alignment tests concluded • Constellation #4 • Some failure cases finished 03. November 2006 | PM2 E2Eplus | page 3

  4. Constellations #3 and #4 03. November 2006 | PM2 E2Eplus | page 4

  5. Constellations #3 and #4 • Constellation #3 • Essentially similar to constellation #2, but using new orbit propagation method • Data only used for test purposes. This constellation will not be considered further • Constellation #4 • Launch on July 1, 1998 (1.5 years later than in Phase A, to account for launch delay) • Inclination Swarm A+B: 87.4ºSwarm C: 88.0º • Initial altitude: 450 km (A+B) and 530 km (C) • Longitudinal difference between Swarm A and B: 1.4º 03. November 2006 | PM2 E2Eplus | page 5

  6. Solar and geomagnetic activity 03. November 2006 | PM2 E2Eplus | page 6

  7. Orbit decay for Swarm A, for various launch times 03. November 2006 | PM2 E2Eplus | page 7

  8. Problem: Different crustal field recovery for Constellations 3 and 4 Signal contains core, lithospheric and magnetospheric (primary and induced) field Constellation 3 Constellation 4 Reason: few data at the end of C#4 with the usual quiet-time selection criteria! 03. November 2006 | PM2 E2Eplus | page 8

  9. Altitude evolution for Swarm A, last 3 months 03. November 2006 | PM2 E2Eplus | page 9

  10. Altitude evolution for Swarm A, last 3 months 03. November 2006 | PM2 E2Eplus | page 10

  11. Altitude evolution for Swarm A, last 3 months 03. November 2006 | PM2 E2Eplus | page 11

  12. Filter Gain 03. November 2006 | PM2 E2Eplus | page 12

  13. Crustal field recovery for Constellation 4 Signal contains core, lithospheric and magnetospheric (primary and induced) field C#4, usual selection criteria C#4, relaxed selection criteria 03. November 2006 | PM2 E2Eplus | page 13

  14. True C4 C4-a C4 C4-a Crustal field recovery for Constellation 4 Signal contains core, lithospheric and magnetospheric (primary and induced) field Power spectra Correlation coefficient C4: usual selection criteria // C4-a: relaxed selection criteria 03. November 2006 | PM2 E2Eplus | page 14

  15. Crustal field recovery for Constellations 3 and 4 Input data contain all, misaligned signal, including toroidal field and noise Model includes solving for multi Euler angle bins Constellation 3 Constellation 4 03. November 2006 | PM2 E2Eplus | page 15

  16. Multi Euler angle recovery for Constellation 4 Input data contain all, misaligned signal, including toroidal field and noise Solving for multi Euler bins Length bin: 30 days 03. November 2006 | PM2 E2Eplus | page 16

  17. Map of Crustal Field Difference in Br 03. November 2006 | PM2 E2Eplus | page 17

  18. Model estimation in VFM, resp. CRF Frame • Model estimation in VFM frame is unstable (product of p and e) • Model estimation in non-VFM frame (CRF or NEC) is stable 03. November 2006 | PM2 E2Eplus | page 18

  19. Failure and imperfection cases 03. November 2006 | PM2 E2Eplus | page 19

  20. Failure and Imperfection Cases • Failure of VFM and/or STR on a single satellite • Only scalar (no vector) data available for Swarm A • Only scalar (no vector) data available for Swarm C • Impact of a S/C magnetic field on a single satellite (Swarm A) • Constant S/C dipole moment (hard magnetization), corresponding to 2 nT at the location of the ASM • Induced S/C dipole moment (soft magnetization), corresponding to 3 nT at the location of the ASM over the poles (i.e. the area of maximum Earth’s magnetic field strength) • Time dependent disturbance at ASM position of the form 1 sin(2pt/24) + 1 sin(2pT/24) nT • Noise in the CRF attitude of a single satellite (Swarm A) • Time dependent attitude noise (all components) 6 sin(wt) arcsecs + 10 sin(2pT/24) arcsecswhere t is UT, w is orbital frequency, and T is Local Time in hours. • Failure of one or more satellite (extension of Phase A analysis) • Magnetic data from all 3 satellites (Swarm A, B and C) • Magnetic data from Swarm A and C only • Magnetic data from Swarm A and B only • Magnetic data from Swarm A only 03. November 2006 | PM2 E2Eplus | page 20

  21. Failure and Imperfection Cases Failure case 1.a : Vector data from Swarm A and C, scalar data from Swarm B Input data contain all, misaligned signal, including toroidal field and noise Model includes solving for multi Euler angle bins 03. November 2006 | PM2 E2Eplus | page 21

  22. Failure and Imperfection Cases Failure case 1.a : Vector data from Swarm A and C, scalar data from Swarm B Input data contain all, misaligned signal, including toroidal field and noise Model includes solving for multi Euler angle bins 03. November 2006 | PM2 E2Eplus | page 22

  23. Failure and Imperfection Cases Constellation 4 (vector data from all three satellites) vs. failure case 1.a (vector data from Swarm A and C, scalar data from Swarm B) 03. November 2006 | PM2 E2Eplus | page 23

  24. Failure and Imperfection Cases Failure case 4.b : Vector data from Swarm A and C only (failure of Swarm B) Input data contain all, misaligned signal, including toroidal field and noise Model includes solving for multi Euler angle bins 03. November 2006 | PM2 E2Eplus | page 24

  25. Failure and Imperfection Cases Failure case 4.b : Vector data from Swarm A and C only (failure of Swarm B) Input data contain all, misaligned signal, including toroidal field and noise Model includes solving for multi Euler angle bins 03. November 2006 | PM2 E2Eplus | page 25

  26. Failure and Imperfection Cases Constellation 4 (vector data from all three satellites) vs. failure case 4.b (vector data from Swarm A and C only, failure of Swarm B) 03. November 2006 | PM2 E2Eplus | page 26

  27. Failure and Imperfection Cases Failure case 1.a (vector data from Swarm A and C, scalar data from Swarm B) vs. failure case 4.b (vector data from Swarm A and C only, failure of Swarm B) Input data contain all, misaligned signal, including toroidal field and noise Model includes solving for multi Euler angle bins 03. November 2006 | PM2 E2Eplus | page 27

  28. Failure and Imperfection Cases Failure case 4.d : Vector data from Swarm A only (failure of Swarm B and C) Input data contain all, misaligned signal, including toroidal field and noise Model includes solving for multi Euler angle bins 03. November 2006 | PM2 E2Eplus | page 28

  29. Failure and Imperfection Cases Failure case 4.d : Vector data from Swarm A only (failure of Swarm B and C) Input data contain all, misaligned signal, including toroidal field and noise Model includes solving for multi Euler angle bins 03. November 2006 | PM2 E2Eplus | page 29

  30. Failure and Imperfection Cases Constellation 4 (vector data from all three satellites) vs. failure case 4.d (vector data from Swarm A only, failure of Swarm B and C) 03. November 2006 | PM2 E2Eplus | page 30

  31. Failure and Imperfection Cases Failure case 4.b (vector data from Swarm A and C only, failure of Swarm B) vs. failure case 4.d (vector data from Swarm A only, failure of Swarm B and C) Input data contain all, misaligned signal, including toroidal field and noise Model includes solving for multi Euler angle bins 03. November 2006 | PM2 E2Eplus | page 31

  32. Map of Crustal Field Difference in Br Optimal (non gradient) Failure Case 1a Failure Case 4b Failure Case 4d 03. November 2006 | PM2 E2Eplus | page 32

  33. Summary: Lithospheric Field Recovery 03. November 2006 | PM2 E2Eplus | page 33

  34. Summary: Secular Variation Recovery 03. November 2006 | PM2 E2Eplus | page 34

  35. Results: Gradient approach, Cons #3 03. November 2006 | PM2 E2Eplus | page 35

  36. Map of Crustal Field Difference in Br Constellation #3 Field 03. November 2006 | PM2 E2Eplus | page 36

  37. Map of Crustal Field Difference in Br Constellation #3 Field Constellation #3 Gradient 03. November 2006 | PM2 E2Eplus | page 37

  38. Plans for the near Future • GUC, The Great Unified Code: Combination of gradient and multi-satellite alignment • Code ready, but first tests using Cons #4 not successful • Could be due to N-S shift between Swarm A and B of Cons #4 • Test using Cons #3 (Swarm A and B side-by-side) ongoing • Cons #4 may require time-shift of Swarm B data (to make A+B flying side-by-side) • Completion of remaining imperfection and failure scenarii • Non-gradient scenarii (1a, 4b, 4d) done • The other cases require GUC solution • Final Presentation: Beginning of 2007 03. November 2006 | PM2 E2Eplus | page 38

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